1. Field of the Invention
The present invention relates to a mechanism of reclining a vehicular seat.
2. Description of the Related Art
In related arts, various modes are adopted for a reclining mechanism provided at a seat frame of a vehicle. A basic structure thereof is constituted by a casing on one side having a hole for an operating shaft, a gear plate having an internal gear provided at the casing on one side, a lock gear plate having a gear brought in mesh with the internal gear of the gear plate, a cam cooperatively operating with the lock gear plate via a locking pin or slidable contact and a spiral spring governing recovery of the cam. Therefore, the lock gear is moved in an up and down direction by movement of the cam in the clockwise direction (as an example). There is constituted a structure which is locked by bringing the lock gear and the internal gear in mesh with each other and unlocked conversely by separating the lock gear from the internal gear by the movement in the up and down direction. Further, the spiral spring is used for achieving firm and smooth recovery of the cam.
A problem of the conventional structure explained above will be pointed out. First, there is constructed a structure in which the lock gear plate is moved by moving the cam, the moving member and the locking pin, further, the lock gear plate is recovered by recovering the spinal spring and moving the cam, the moving member and the locking pin. Therefore, it is pointed out that movement of the locking pin and the cam is not smooth, the unlocking operation is not carried out firmly and pertinently, recovery of the spiral spring is not smooth and the locking operation is not carried out firmly and pertinently. Next, there is constructed a structure in which the lock gear plate is moved by sliding contact of the lock gear plate with an open peripheral face of the cam and the lock gear plate is recovered by recovering the coil spring and by way of a lock peripheral face of the cam. Therefore, it is pointed out that the locking or the unlocking operation is carried out by individually operating recovery of the coil spring and rotation of the cam and therefore, the locking or the unlocking operation cannot be carried out firmly and pertinently.
Further, the following inventions are pointed out as related literatures.
Literature (1) is a reclining apparatus of JP-A-2000-102440 and a content thereof is a unitized reclining apparatus having a constitution for providing a base plate having a lock gear, a gear plate having an inner teeth and a spring locking the base plate and the gear plate by bringing the inner teeth and an outer teeth of the lock gear in mesh with each other, rotating a seat by ensuring to unlock the seat by opening the mesh by rotating a cam and recovering the cam, wherein the cam is recovered by reaction force of the spring, initial locking is ensured by the mesh of the base plate and the gear plate and a stopper member attachable to and detachable from a guide groove of the gear plate is provided and is a reclining apparatus capable of arbitrarily setting a reclinable range of a seat back and capable of being commonly used even for a seat of an automobile of a different vehicle kind.
Literature (2) is a hinge mechanism for a seat for a vehicle and a vehicular seat having such a mechanism of JP-A-11-70028, as a content thereof, a hinge mechanism is provided with a slug with teeth moving at a fixed side face plate (progressing in a circumferential direction or regressing in a center direction), the slug with teeth is made movable at a face of the fixed side face plate by way of a restriction of the fixed side face plate. Therefore, the slug with teeth progresses on the face of the fixed side face plate via a cam, a peg and a plate and locks movement of a seat, further, the slug with teeth is constituted to regress on the face of the fixed side face plate via the cam, the peg and the plate as well as a spring and unlocks movement of the seat and when a back rest is fallen forwardly and thereafter made to rise, a position of the backrest which has been adjusted lastly can be automatically recovered to be locked, further, the hinge mechanism for a vehicular seat having strength equivalent to that of a conventional product is provided.
Literature (3) is a seat reclining apparatus of JP-A-10-71042 and a content thereof is a reclining mechanism constituted by an upper arm, a lower arm and a restricting member, the reclining mechanism is provided with pairs of ratchets having inner teeth and movable poles in mesh with the inner teeth, constituted by a cam with arm for moving the pole and a spring for restricting mesh of the ratchet and the inner teeth, and the pole is moved in an up and down direction by locking the inclined arm portion provided at the cam and an inclined arm groove provided at the pole and moving the arm portion of the cam. Further, there is provided the seat reclining apparatus constituted by bringing the inner teeth and an outer teeth of the pole by making the pole progress, locking the movement of the seat, opening the mesh between the inner teeth and the outer teeth of the pole by making the pole regress and unlocking movement of the seat and having sufficient rigidity against load applied on a seat back.
In sum, the inventions of literatures (1) through (3) are constructed by a constitution of locking or unlocking the seat by bringing the cam rotated by the operating shaft, the teeth portion of the lock gear moved in the up and down direction via the movement of the cam and the internal gear in mesh with the lock gear or by releasing the mesh. Further, the mesh is carried out by operating the operating shaft and the movement of the cam rotated against reaction force of the spring and the mesh is released by recovering the operating shaft and the cam rotated reversely by the reaction force of the spring.
That is, the above-described inventions of literatures (1) through (3) are constructed by the constitution of moving the lock gear by the movement of the cam by the operating shaft and the both members are constructed by a constitution of cooperatively moving via face contact. Therefore, there are conceivable problems that the movement of the operating shaft is not firmly transmitted to the lock gear, firm movement in a front and rear direction of the seat is not ensured, a failure is caused depending on a frequency of use, or smooth movement of the lock gear is not guaranteed, for example, a strange feeling is felt in-the movement of the seat.
Embodiments of the invention will be explained as follows. In a state of FIG. 1, FIG. 5 or FIG. 6, is a state in which operating means (not illustrated) for operating a reclining mechanism is free (a state in which back rest is erected), an operating shaft is stopped and the state is a so-to-speak state of fixing a seat (is not pivoted). In the state, a lock face of a lock gear plate and a lock face of a cam are brought into a relationship of face contact, the lock gear plate is disposed on an upper side and a gear of the lock gear plate and an internal gear of a gear plate are brought into a mesh relationship. Therefore, a fixed state (locked state) of the seat is held by the mesh relationship of the cam, a spring and the gear. Further, an operating portion of the spring is disposed at an unlock face of the cam and brought into a relaxed state (main body portion is brought into substantially a linear state) and two end portions of the spring are inserted into a locking hole of the lock gear plate in a loosely fitted state. Further, in an actual apparatus, it can be recognized that a lock state is ensured in a range of around angle A of the operating shaft (as an example: the same as follows).
In operating the reclining mechanism (moving the seat), when the operating means is grabbed and the operating means is pivoted in either of directions, the operating shaft is rotated (the operating shaft can automatically be operated). By rotating the operating shaft, the cam is rotated. Therefore, a face contact relationship between a lock face of the cam and a lock face of the lock gear plate is lost. Further, by further rotating the cam, there is brought about a state of pressing the operating portion of the spring by the lock face of the cam and the operating portion is moved (bent) in an outer peripheral direction of the cam. Further, in accordance with the operation, the two end portions are moved to an axis core direction (inner direction) of the cam and the lock gear plate is pulled down in accordance with the movement. By pulling down the lock gear plate, the seat is moved by releasing the mesh relationship between the gear of the lock gear plate and the internal gear of the gear plate. That is, the operating shaft falls in a range of around angle B and movement of the seat is ensured. Thereafter, by rotating the operating shaft further, free movement of the gear plate (unlocked state) is guaranteed and the movement of the seat becomes a final stage. Further, in the actual apparatus, in a range of around angle C of the operating shaft, it can be recognized that the unlocked state is ensured.
Further, in recovering the seat from the moved state to the initial state, by releasing the operation with respect to the operating shaft or recovering automatically, the cam is rotated, when the cam presses the lock face, the operating portion of the spring is released, the operating portion is recovered, the spring is successively recovered, the lock gear plate is moved in a direction opposed to the axis core (outer direction) and the lock gear plate is pushed up in accordance with the movement. By pushing up the lock gear plate, the mesh relationship between the gear of the lock gear plate and the internal gear of the gear plate is brought about, finally, the initial state is recovered.